1. Field of the Invention
The present invention relates to an image capture apparatus having a vibration correction function, and a control method of the image capture apparatus.
2. Description of the Related Art
As one of vibration correction devices incorporated in image capture apparatuses, for example, digital cameras, video cameras or the like, an optical vibration correction device is known. An optical vibration correction device performs vibration correction by driving part of (hereinafter referred to as a shift lens) an image capture lens in a direction perpendicular to the optical axis for changing the optical axis. Such vibration correction devices detect vibrations from a photographer's hand using an angular velocity sensor and drive the shift lens so as to correct the detected vibration, thereby achieving vibration correction.
The vibration detected by the angular velocity sensor is vibration involving the image capture apparatus' rotational direction (rotational vibration). In ordinary use, correcting this vibration achieves a sufficient image stabilization effect. However, if an object to be captured is in close proximity to the image capture apparatus (i.e., in the case of macro-image capture) or the lens has a particularly high zoom factor, vibration components increase due to an influence of “parallel vibration” which is caused by parallel movement of the image capture apparatus. When the influence of parallel vibration becomes large, vibration cannot be detected by the angular velocity sensor. In view of this, there is a proposed technique for using both an angular velocity sensor and an acceleration sensor for detecting rotational vibration and parallel vibration, and correcting them (Japanese Patent Laid-Open No. 2006-3439).
Furthermore, the following method is also proposed as a parallel vibration correction method without using a sensor such as an acceleration sensor. More specifically, in addition to vibration detector such as an angular velocity sensor, an image sensor for detecting a motion vector of the entire image is separately provided. An output of the angular velocity sensor is subtracted from the motion vector of the entire image for extracting the parallel vibration components, and a correction amount is calculated based on the parallel vibration (Japanese Patent Laid-Open No. 2009-105784).
Moreover, there is a proposed method, in a case of taking macro-image, which suggests the superimposition of a plurality of numbers of images in order to reduce vibration caused by an influence of parallel vibration (Japanese Patent Laid-Open No. 2009-171327).
However, the above-described conventional methods require an acceleration sensor or an additional image sensor for detecting parallel vibration. Furthermore, although vibration detection can be realized without an additional structure in image superimposition using firmware, problems of long processing time and unstable correction effects still remain.